A variety of implantable medical devices (IMDs) are commercially available for monitoring physiological signals. Such devices can be configured for delivering therapies, such as cardiac pacemakers and defibrillators, hemodynamic monitors, drug delivery devices, insulin monitors and pumps, neurostimulators, and muscle stimulators. These devices may detect clinically serious or life-threatening conditions related to physiological events or conditions. Such devices are also typically enabled to perform self-diagnostic tests or otherwise monitor device performance issues, such as battery life-expectancy, electrical lead impedance, frequency of delivered therapies, and so on. The advanced capabilities of IMDs in detecting physiological or device-related conditions that may warrant careful monitoring, clinical attention or even emergency care has motivated the addition of real time patient notification features to IMD systems.
Home monitors are external devices that can communicate with the IMD to retrieve data relating to device performance or physiological conditions. The use of home monitors for displaying or broadcasting a patient warning or notification has been proposed, such that the patient is aware of a condition that warrants further monitoring or attention. The home monitor is generally coupled to a communication network to transmit IMD data via the communication network to a remote patient management center. Health care professionals can thereby respond appropriately to the device-related and physiological data retrieved. Interrogation of the IMD by the home monitor and transfer of data to the remote patient management center can occur on a scheduled, periodic basis.
The IMD may be enabled to transmit data to the home monitor upon detecting a triggering event corresponding to a predetermined alert condition. A real-time warning alerts the patient that a condition requiring medical attention or warranting close monitoring or action by the patient has been detected. The home monitor may display a notification of the alert condition to the patient or other caregiver and/or transmit the data to the remote patient management center. However, further updates of the parameter causing the alert condition are generally not be available. The patient or clinician is not notified if the alert condition persists for a period of time or if the alert condition is no longer present. Updated data may not be remotely retrieved from the IMD until another triggering event, the next scheduled interrogation session or until a clinician manually schedules an interrogation.